Littelfuse T2000.0020 - Reverse Power Relay. 400/450V L-L 5A. Protects the generator from being run as a motor. The Reverse Power Relay T2000 will protect the generator from being run as an electric motor. The T2000 will protect the prime mover of the generator against physical damage, but will also protect the parallel running generators from overload caused by the inversed load shift in a reverse power situation. T2000 reverse power relay function: The T2000 measures the current through an external 5A CT attached on phase L1. The phase angle (phi) is determined from the voltage measurement across L1 and L2. The T2000 calculates the active current as I x cos phi. If the active current becomes negative and exceeds the preset level (2 – 20 percent), the pick-up LED will activate and the trip delay timer (2 – 20 seconds) will also activate. The built-in trip relay will energize after the delay has passed, provided that the preset trip level was continuously exceeded during the time of the delay.
Littelfuse

T2000.0020

UPC: 079458962468

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Overview

The Littelfuse T2000.0020 Reverse Power Relay (SKU: T2000.0020) is engineered to prevent generators from operating as electric motors, a critical failure mode that can cause significant damage. This relay is designed for 400/450V L-L applications and utilizes an external 5A Current Transformer (CT) on phase L1 to measure current. The phase angle (phi) is determined by measuring the voltage across L1 and L2. The T2000 calculates the active current using the formula I x cos phi. When this active current becomes negative and exceeds a user-defined threshold, ranging from 2% to 20% of the nominal current, the relay's pick-up LED illuminates, and a trip delay timer activates. This timer is also configurable, with a range of 2 to 20 seconds. If the negative active current condition persists for the duration of the set delay, the built-in trip relay will energize. This action effectively disconnects the generator, protecting the prime mover from physical damage and preventing parallel running generators from being overloaded due to an inverted load shift. The T2000.0020 is essential for maintaining the integrity and operational reliability of generator sets in industrial and commercial power systems.
  • Protects generators from operating as electric motors.
  • 400/450V L-L operating voltage.
  • Utilizes external 5A CT on Phase L1 for current measurement.
  • Adjustable trip level (2-20%) and trip delay (2-20 seconds).
  • Built-in trip relay for generator disconnection.

Specifications

Application
Industrial
Brand Name
Littelfuse
Current Rating
5 A
Series
T2000
Special Features
High Quality
Sub Brand
Relay Series
Type
Protection Relays and Controls
Voltage Rating
400/450 V L-L
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Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.